My Coumpuer...  

Hey there and welcome to myLot

I guess in terms of upgrades it depends on what you're using your computer for. Here's my system. Keep in mind i do a LOT of high end work in digital photography, print work, media and gaming all in one.

Intel Pentium 4 3.2 GHZ Processor
Creative Labs SoundMax soundcard (5.1 surroud)
nVidia BFG GeForce 7600 GS OC video card (512mb)
TV tuner
250GB HD
2GB RAM
4 Fan cooling system + lighting
Windows XP Pro O/S

this is my rig but it all depends on what you use your computer for.

The only true thing that concerns me with your computer is the fact that you are still running an Intel Pentium D CPU with a Vista system. Even though Windows Vista Home Premium edition is not as demanding as Windows Vista Ultimate- you still will not get your systems full potential out unless you are running Intel's new line of processing chips- the dual core. The only problem with changing between the Pentium D and the Dual Core, is the fact that the chips are not interchangable. Meaning, if you upgrade your process, you will also have to upgrade your mother board, and thus upgrading your graphics card as well. It would probably be a good idea anyways, considering the fact that companies are starting to shift to this new Direct X 10 idea. I would suggest getting you a PCI EXPRESS base graphics card. This will be compatable with your new motherboard. As far as your memory goes, if you were to descide to upgrade, you would more then likely have to upgrade your RAM as well. The new motherboards run what is known as DDR 2. And usually a Pentium D compatible motherboard runs DDR, which does not have the right slot fit for DDR2. I know it seems like a lot of work, however, everyone has to upgrade eventually.

AMD Athlon 2500Xp
MSI KM400 Mother Board.
512 Mb Ram.
256 MB Gforce 5200 VGA card
120GB
DVD ROM
CD ROM
17 Flat Monitor
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Do you have a DVD-Writer? It's the most important device to prevent your Hard-disk from getting full with data, although 200 Gb may appear to be sufficient to you at present. Also, do you have a Graphics Card? If you are using Graphics Softwares like Adobe Photoshop CS3, 3D Studio Max, Maya , etc. or playing games like X-Men, Scarface, and other new games, you will of course feel the difference with a 512 MB GeForce Card. It all depends on what you are doing on your PC. For people using MSOffice and doing simple programming or browsing the internet it doesn't matter much. So first you should lay down your requirements, and then analyse your PC, and this applies not only to you but to everybody there using a PC.